with kindle it isn't too bad i can always download them again same for those books i've bought from Baen and transferred across (bassicly every RFC book but for the safehold ones), though it will take a bit longer.

that is 90% of my ebooks, there are some WH40K that i bought directly from black library rather then apple, but again i can do much the same as i would for the Baen books.

I worry more about loosing all my music. i ripped music from CDs for years before MP3 downloads from amazon or itunes came along.

Depending on what I want to backup I either use Google Drive for stuff that doesn't contain personal information or Resilio (formerly BT Sync) for stuff I want to keep private. Resilio syncs folders strictly between computers you choose, so I have it running on all my computers which means I always have multiple copies of my personal stuff.

For large amounts of data I have a 20TB RAID5 system with double spares that I built myself. I usually mirror my primary computer to it regularly with Disk2Vhd, so if my computer goes belly up I can always mount the VHD in a virtual machine on any computer and continue working until I can mirror the VHD to a new disk/computer.

Considering the amount of eBooks I bought I'm feeling safe and since a fair amount of them are bought from Baen I feel doubly safe since you can always log in and download them again.

"After a certain period, the rights to a book revert back to the author from the publisher. At that point, the author can choose the next step for his or her work, which sometimes means that Baen Ebooks can no longer offer it for sale. In most cases, any book that you have already purchased should remain accessible to you through your account.We recommend all customers to keep backups of their purchased Ebooks as it is not always possible for us to host Ebooks after their rights are reverted. Further, we cannot always give advance notice when a book’s rights will be reverted.If you can no longer access a purchased Ebook, email us with your Baen Ebooks email address and the original order number. You can contact us by clicking on the “Contact Technical Support” question at the bottom of this page.We apologize for any inconvenience. Note that if a particular book you are looking for has become unavailable on our site, you might be able to find it for sale elsewhere."

That is why I not only have a backup of my drive, but periodically copy all my e-books to a cd-rom.

Starkiller wrote:That is why I not only have a backup of my drive, but periodically copy all my e-books to a cd-rom.

I do hope you re-transfer old CD's to new ones. Unless you have bought the really expensive type that are intended for archival storage they will degrade over the years until they can't be read anymore.

It should be noted though that there aren't many studies done on the longevity of optical media, but expect about 20 years for cd-rom's. From personal experience I know the longevity hinges on the quality of the writer AND at which speed the disc was written.

I still have a functional gold cd from Kodak that was written in the mid 90's. The semi-professional cd-writers had just hit the market, about USD 5000 for the hardware and another USD 5000 for the software and it had a max write speed of x2. We later got an upgrade that managed x4.

I do hope you re-transfer old CD's to new ones. Unless you have bought the really expensive type that are intended for archival storage they will degrade over the years until they can't be read anymore.

I do - I create a new CD each year covering all the books on my hard drive, as well as keep two sd's for my Nook reader.

I also imaged the main drive of my computer - unfortunately the time before last I left the portable drive out and the cleaning lady dropped it, cracking the case and ruining the drive, so I had to buy a new hard drive and create an new image -unfortunately the original image is gone.